So insightful! It took me a while to get a "feel" for what you are saying; but you put it into words perfectly. This is especially difficult in situations like baristas or service workers of places I frequent.

One day I might be gregarious and have a conversation with the person, but most of the time I just want to get my coffee and be on my way. I've already planned my next couple steps; and stopping to chat wasn't one of them.

Then, every time I go to this place, it's a weird interaction with the service worker because I didn't pick the conversation up where we last left it, or I didn't show a keen interest in them that day. It leads to them avoiding eye-contact or "going on break" when your next in line.

So I try extra hard now to just keep to my own and not talk to anyone for the most part. Not out of being anti-social, but just knowing that I most likely won't benefit from the interaction in the long run.